content: /* ===========================================================
   * JFreeChart : a free chart library for the Java(tm) platform
   * ===========================================================
   *
   * (C) Copyright 2000-2012, by Object Refinery Limited and Contributors.
   *
   * Project Info:  http://www.jfree.org/jfreechart/index.html
   *
   * This library is free software; you can redistribute it and/or modify it
   * under the terms of the GNU Lesser General Public License as published by
   * the Free Software Foundation; either version 2.1 of the License, or
   * (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful, but
   * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
   * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
   * License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
   * USA.
   *
   * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
   * Other names may be trademarks of their respective owners.]
   *
   * -----------
   * Series.java
   * -----------
   * (C) Copyright 2001-2012, by Object Refinery Limited.
   *
   * Original Author:  David Gilbert (for Object Refinery Limited);
   * Contributor(s):   -;
   *
   * Changes
   * -------
   * 15-Nov-2001 : Version 1 (DG);
   * 29-Nov-2001 : Added cloning and property change support (DG);
   * 30-Jan-2002 : Added a description attribute and changed the constructors to
   *               protected (DG);
   * 07-Oct-2002 : Fixed errors reported by Checkstyle (DG);
   * 13-Mar-2003 : Implemented Serializable (DG);
   * 01-May-2003 : Added equals() method (DG);
   * 26-Jun-2003 : Changed listener list to use EventListenerList - see bug
   *               757027 (DG);
   * 15-Oct-2003 : Added a flag to control whether or not change events are sent
   *               to registered listeners (DG);
   * 19-May-2005 : Made abstract (DG);
   * ------------- JFREECHART 1.0.x ---------------------------------------------
   * 04-May-2006 : Updated API docs (DG);
   * 26-Sep-2007 : Added isEmpty() and getItemCount() methods (DG);
   * 16-Oct-2011 : Added vetoable property change support for series name (DG);
   * 17-Jun-2012 : Removed JCommon dependencies (DG);
   * 
   */
  
  package org.jfree.data.general;
  
  import java.beans.PropertyChangeListener;
  import java.beans.PropertyChangeSupport;
  import java.beans.PropertyVetoException;
  import java.beans.VetoableChangeListener;
  import java.beans.VetoableChangeSupport;
  import java.io.Serializable;
  
  import javax.swing.event.EventListenerList;
  
  import org.jfree.chart.util.ObjectUtilities;
  import org.jfree.chart.util.ParamChecks;
  
  /**
   * Base class representing a data series.  Subclasses are left to implement the
   * actual data structures.
   * <P>
   * The series has two properties ("Key" and "Description") for which you can
   * register a <code>PropertyChangeListener</code>.
   * <P>
   * You can also register a {@link SeriesChangeListener} to receive notification
   * of changes to the series data.
   */
  public abstract class Series implements Cloneable, Serializable {
  
      /** For serialization. */
      private static final long serialVersionUID = -6906561437538683581L;
  
      /** The key for the series. */
      private Comparable key;
  
      /** A description of the series. */
      private String description;
  
      /** Storage for registered change listeners. */
      private EventListenerList listeners;
  
      /** Object to support property change notification. */
      private PropertyChangeSupport propertyChangeSupport;
  
      /** Object to support property change notification. */
      private VetoableChangeSupport vetoableChangeSupport;
  
      /** A flag that controls whether or not changes are notified. */
      private boolean notify;
  
      /**
       * Creates a new series with the specified key.
       *
       * @param key  the series key (<code>null</code> not permitted).
       */
      protected Series(Comparable key) {
          this(key, null);
      }
  
      /**
       * Creates a new series with the specified key and description.
       *
       * @param key  the series key (<code>null</code> NOT permitted).
       * @param description  the series description (<code>null</code> permitted).
       */
      protected Series(Comparable key, String description) {
          ParamChecks.nullNotPermitted(key, "key");       
          this.key = key;
          this.description = description;
          this.listeners = new EventListenerList();
          this.propertyChangeSupport = new PropertyChangeSupport(this);
          this.vetoableChangeSupport = new VetoableChangeSupport(this);
          this.notify = true;
      }
  
      /**
       * Returns the key for the series.
       *
       * @return The series key (never <code>null</code>).
       *
       * @see #setKey(Comparable)
       */
      public Comparable getKey() {
          return this.key;
      }
  
      /**
       * Sets the key for the series and sends a <code>VetoableChangeEvent</code>
       * (with the property name "Key") to all registered listeners.  If the
       * change is vetoed by a listener, this method will throw an 
       * IllegalArgumentException.
       *
       * @param key  the key (<code>null</code> not permitted).
       *
       * @see #getKey()
       */
      public void setKey(Comparable key) {
          ParamChecks.nullNotPermitted(key, "key");
          Comparable old = this.key;
          try {
              // if this series belongs to a dataset, the dataset might veto the
              // change if it results in two series within the dataset having the
              // same key
              this.vetoableChangeSupport.fireVetoableChange("Key", old, key);
              this.key = key;
          } catch (PropertyVetoException e) {
              throw new IllegalArgumentException(e);
          }
      }
  
      /**
       * Returns a description of the series.
       *
       * @return The series description (possibly <code>null</code>).
       *
       * @see #setDescription(String)
       */
      public String getDescription() {
          return this.description;
      }
  
      /**
       * Sets the description of the series and sends a
       * <code>PropertyChangeEvent</code> to all registered listeners.
       *
       * @param description  the description (<code>null</code> permitted).
       *
       * @see #getDescription()
       */
      public void setDescription(String description) {
          String old = this.description;
          this.description = description;
          this.propertyChangeSupport.firePropertyChange("Description", old,
                  description);
      }
  
      /**
       * Returns the flag that controls whether or not change events are sent to
       * registered listeners.
       *
       * @return A boolean.
       *
       * @see #setNotify(boolean)
       */
      public boolean getNotify() {
          return this.notify;
      }
  
      /**
       * Sets the flag that controls whether or not change events are sent to
       * registered listeners.
       *
       * @param notify  the new value of the flag.
       *
       * @see #getNotify()
       */
      public void setNotify(boolean notify) {
          if (this.notify != notify) {
              this.notify = notify;
              fireSeriesChanged();
          }
      }
  
      /**
       * Returns <code>true</code> if the series contains no data items, and
       * <code>false</code> otherwise.
       *
       * @return A boolean.
       *
       * @since 1.0.7
       */
      public boolean isEmpty() {
          return (getItemCount() == 0);
      }
  
      /**
       * Returns the number of data items in the series.
       *
       * @return The number of data items in the series.
       */
      public abstract int getItemCount();
  
      /**
       * Returns a clone of the series.
       * <P>
       * Notes:
       * <ul>
       * <li>No need to clone the name or description, since String object is
       * immutable.</li>
       * <li>We set the listener list to empty, since the listeners did not
       * register with the clone.</li>
       * <li>Same applies to the PropertyChangeSupport instance.</li>
       * </ul>
       *
       * @return A clone of the series.
       *
       * @throws CloneNotSupportedException  not thrown by this class, but
       *         subclasses may differ.
       */
      @Override
      public Object clone() throws CloneNotSupportedException {
          Series clone = (Series) super.clone();
          clone.listeners = new EventListenerList();
          clone.propertyChangeSupport = new PropertyChangeSupport(clone);
          clone.vetoableChangeSupport = new VetoableChangeSupport(clone);
          return clone;
      }
  
      /**
       * Tests the series for equality with another object.
       *
       * @param obj  the object (<code>null</code> permitted).
       *
       * @return <code>true</code> or <code>false</code>.
       */
      @Override
      public boolean equals(Object obj) {
          if (obj == this) {
              return true;
          }
          if (!(obj instanceof Series)) {
              return false;
          }
          Series that = (Series) obj;
          if (!getKey().equals(that.getKey())) {
              return false;
          }
          if (!ObjectUtilities.equal(getDescription(), that.getDescription())) {
              return false;
          }
          return true;
      }
  
      /**
       * Returns a hash code.
       *
       * @return A hash code.
       */
      @Override
      public int hashCode() {
          int result;
          result = this.key.hashCode();
          result = 29 * result + (this.description != null
                  ? this.description.hashCode() : 0);
          return result;
      }
  
      /**
       * Registers an object with this series, to receive notification whenever
       * the series changes.
       * <P>
       * Objects being registered must implement the {@link SeriesChangeListener}
       * interface.
       *
       * @param listener  the listener to register.
       */
      public void addChangeListener(SeriesChangeListener listener) {
          this.listeners.add(SeriesChangeListener.class, listener);
      }
  
      /**
       * Deregisters an object, so that it not longer receives notification
       * whenever the series changes.
       *
       * @param listener  the listener to deregister.
       */
      public void removeChangeListener(SeriesChangeListener listener) {
          this.listeners.remove(SeriesChangeListener.class, listener);
      }
  
      /**
       * General method for signalling to registered listeners that the series
       * has been changed.
       */
      public void fireSeriesChanged() {
          if (this.notify) {
              notifyListeners(new SeriesChangeEvent(this));
          }
      }
  
      /**
       * Sends a change event to all registered listeners.
       *
       * @param event  contains information about the event that triggered the
       *               notification.
       */
      protected void notifyListeners(SeriesChangeEvent event) {
  
          Object[] listenerList = this.listeners.getListenerList();
          for (int i = listenerList.length - 2; i >= 0; i -= 2) {
              if (listenerList[i] == SeriesChangeListener.class) {
                  ((SeriesChangeListener) listenerList[i + 1]).seriesChanged(
                          event);
              }
          }
  
      }
  
      /**
       * Adds a property change listener to the series.
       *
       * @param listener  the listener.
       */
      public void addPropertyChangeListener(PropertyChangeListener listener) {
          this.propertyChangeSupport.addPropertyChangeListener(listener);
      }
  
      /**
       * Removes a property change listener from the series.
       *
       * @param listener  the listener.
       */
      public void removePropertyChangeListener(PropertyChangeListener listener) {
          this.propertyChangeSupport.removePropertyChangeListener(listener);
      }
  
      /**
       * Fires a property change event.
       *
       * @param property  the property key.
       * @param oldValue  the old value.
       * @param newValue  the new value.
       */
      protected void firePropertyChange(String property, Object oldValue,
              Object newValue) {
          this.propertyChangeSupport.firePropertyChange(property, oldValue,
                  newValue);
      }
      
      /**
       * Adds a vetoable property change listener to the series.
       *
       * @param listener  the listener.
       * 
       * @since 1.0.14
       */
      public void addVetoableChangeListener(VetoableChangeListener listener) {
          this.vetoableChangeSupport.addVetoableChangeListener(listener);
      }
  
      /**
       * Removes a vetoable property change listener from the series.
       *
       * @param listener  the listener.
       * 
       * @since 1.0.14 
       */
      public void removeVetoableChangeListener(VetoableChangeListener listener) {
          this.vetoableChangeSupport.removeVetoableChangeListener(listener);
      }    
  
      /**
       * Fires a vetoable property change event.
       *
       * @param property  the property key.
       * @param oldValue  the old value.
       * @param newValue  the new value.
       */
      protected void fireVetoableChange(String property, Object oldValue,
              Object newValue) throws PropertyVetoException {
          this.vetoableChangeSupport.fireVetoableChange(property, oldValue,
                  newValue);
      }
  
  }
  